Drill and socket construction.



F. G. BGHOLS.

DRILL AND socxn'r CONSTRUCTION. APPLICATION FILB'D D2014, 1910.

1 020 54 Patente d Mar. 19, 1912.

- AL. I MIN I fizvenifor: i" 1 7655275036 am YATES PATENT OFFICE.

FRANCIS G". ECHOLS, O1? HARTFORD, CONNECTICUT, ASSIGNOR TO PRATT & WHITNEY 'COMPANY; OF HARTFORD, CONNECTICUT, A CORPORATION OF NEW JERSEY.

i To all whom z'tmay concern DRILL AND SOCKET CONSTRUCTION.

I Be it known that LFmivcis G. Ecnons, a citizen of the United States, residing at Hartford, in the county of Hartford and State: of Connecticut, have invented certain new and useful Improvements in Drill and Socket Construction, of which the folwlowing is a specification.

This invention relates primarily to a drill and socket construction, although as to all features it is not restricted to drills, but

may be employed in connection with other tools.

Itjs usual to make the interior of a drill socket on a taper, and to correspondinglv externally taper the shank of the drill,

thereby providing a frictional driving rela tiOn between the socket member and the sufficient to produce the frictional grip required to drive the drill. Undue strain is then thrown on the tang, causing the same to break in the socket so as to make removal of the drill diflicult, and in many cases distorting or injuring the drill shank or socket member, or both, so as to render one or both of the parts defective or useless.

I provide a constructioi'i whereby the dif ficulties mentioned are wholly eliminated.

According to one feature of the invention means are provided whereby a grip of the socket upon the drill shank is produced by the relative turning or rotation of the socket: member and drill shank, the construction in its best form being such that, whatever resistance to turning is met by the drill when being forced into a piece of work, there will be automatically and instantaneously produced a corresponding grip of the socket upon the drill shank. This construction is such moreover that the grip due to turning effort or torque is independent of any grip due to endwise pressure, so that even if no endvvise pressure be exerted, as when the point of the drill has passed through the work, there can be no slip of the socket and no undue strain upon any part of either Specifieation of Letters Patent. Patented 11 19, 1912 Application filed December 14; 1910. Serial No. 597,296.

member such as would be apt to distort or destroy either of them.

dVhile in its broader aspects the invention is not restricted to a 'iarticular form of the socket and drill shank, I prefer that these parts he on a taper, one of the parts being provided preferably with projeEting means and the other with a spiral groove to receive said projecting means. so that when any turning etfort is exerted between the parts in the direction required for drilling, the shank will be drawn into the socket and wedged solidly therein. I find that I can secure the best results by locating the projecting means within the socket and by having a spiral groove on the drill shank.

In the drawings accompanying and forming part of the present specification 1 show in detail certain forms of embodiment of the invention which to enable those skilled in the art to practice the same will be set forth fully in the following description, while the novelty of the invention will be ii'icluded in the claims succeeding said description. From these observations it will be apparent that I do not restrict myself to the showing made by said drawings and description.

Referring to said drawings: Figure l is a side elevation of a drill and socket therefor involving my invention. Fig. 2 is a longitudinal seelio'r'lal view of the same. Fig. 3 is a longitudinal sect ional view of the socket. Fig. 4. is an el 1-vation of a modified form of drill. Fig. 5 is an elevation of the .shank of the drill shownin Figs. l and 2.

Like characters refer to like parts throughout the several figures of the drawingx In the drawings the numeral 2 denotes a drill socket which has an 'inwardly tapered opening 3 for receiving thecorrespondingly apered shank l of the drill The shank 4: has a spiral or worm groove 6 therein, and this worm groove may for example be' formed by spirally twisting a flat shank on itself. In Fig. 4, the worm or spiral groove 6 is formed in the shank l of the drill 5 by milling. The groove preferably is of a relatively great pitch so that the drill may he removed by pressure appli d to the end. Cooperative with the worm or spiral groove 6 is an internal projection 7 in the tapered opening 3, and this projection can be obtained in various ways. It is shown in Figs.

'.1, 2 'and 3 as consisting of the-aroundedior substantlally spherical end of a pin.

connect the drill with the socket, the shank Awrll be introduced into the opening 3 in -"such way that the projection 7 will enter the worm or spiral groove 6', and itfollows that ;when the drill is introduced intothe socket and-turned as'by hand, it will be 1 is seated in place;

drawn inward by the cooperation of the spiral'groove and proJectioh 7. The drill will, of course, be turned by hand',-,until it The socket may be 4 mounted in-the usual manner and the drill started'to work on stock, and it will' beevi- '15 dent that if there is any relative turning '-'-motion of the drill and socket, the projec-" Htion 7- and the. spiral groove 6 (or 6') willevident also that this I draw the drill shank into the socket and. the gridater' the resistance met-by thedrill, the

'Inore firmly will the 'lattr'be gripped by the socketinto which it is drawn. It will be ipping action. 'due' tot-he 'turningefiort o thesocket member I upon the drill 'will'be independent of and endwise pressure upon-the drill. Furtherin addition to any'gripping effect due tojany more, itwill beobserved that, while 's'onie torque fmay-be exerted through the '.'pro-- 'jection and groove walls, any strain thus upon the projection or groove walls,- or other parts, 'i'ngure them, or I or eause chatte'rmg'or other defects n cons'uch' as would beapt to distort or throw the drill out of true,

struction 'or operation. 4

I prefer that the worm or spiral portion of the appliance, whether the same be on,

the drill-shank or in the socket, be ofsuch pitch thatthe drill can be freely withdrawn .either by thrust applied to the butt or inner end thereof or a pull upon the body portion thereof. f'lh'e parts areso or ganiz e d in the present lnstancethat-the drill is'r'emoved by thrust applied to the inner or buttend thereof, and forv this purpose the-socket 2 may hare a slot 8 to recelve a drift or'key for attaining the -0b ect 1n question.-

\Vhat I claim is:

1. The combination of an internally '-ta-= pered socket, and a drill having a correspondingly tapered, spiral portion .in' the socket, the latter having a projection co-v operative with said-spiral portion to draw the'tapered portion ofthe drill into 'the socket on the relative rotative motion oitit'he drill and socket, the pitch of said spiral por tion being such asto permit withdrawal of" ;the drill from the socket on the application [of forward endwisethru's't thereto. I

- The b na ion Of'an internally he.

pered socket, and a drill havingfafc0rre-1;. .spo-nd'ingly tapered," spiral portion in "the socket, 't-he tap'eredportionof said drill-lbeing spirally grooved and the socket'havin'g V projecting means therein ex tending-into said 710 "spiral groove-to' thereby draw thejta'peredportion of the drill into thes'ocket on relative rotati've motion' of the drill and socket, the pitchof the grooye' being" such" as 'to permit the shank beings-driven from "the erative position. g I

3. The combination I of an internally ta pered drill socket,anda' drill having a correspondingly tapered spiral portion in the spiralportion, to draw the tapered portionof the drill intofthe socket-"onrelative rota-j tive mot-ion ofthe drill and socket. I. In testimony whereof I afiix mysignati l re' I 'in presence oftwo witnesses.

A FRANCIS I e.- ECHOLS." \Vitnesses: i

I HEATH SUTHERLAND,

U, L RKUM.

75 socket while .said pro-jectingrneans is op- 8.0- socket, thei latter' having internallyfixed projecting means ,coiiperat1ng with said;- 

